Systems and methods herein generally relate to printing and scanning systems/methods and more particularly to reducing ambiguity in aligning images.
It is often useful to align a photo (from a scanner, mobile phone, camera, etc.) with a template, since that puts all the regions of interest on the photo in a known location. This usually involves finding features in the photo corresponding to features in the template. This gives a set of displacement vectors. A warping process is fit to the displacement vectors and used to warp the photo into alignment with the template. However quite often, there are many features in the photo that look like the corresponding feature in the template and it is not clear which one is the right one. Also, there may be features in the photo that are not in the template, for example, when comparing a filled-in form with the original template.
Aligning a filled in form with a template is a first step in extracting the information from the form. It is difficult to do this for a cell phone photo of a document lying on a desk since the document generally does not lie flat and the optical axis of the cell phone is generally not perpendicular to the document. Therefore there is a need for a process that can quickly align a photo with a template with high accuracy.